CONCORD — A 33-year-old medical technician who worked at Exeter Hospital has been arrested and charged with spreading hepatitis C to 30 patients through the use of stolen hospital drugs.

David Matthew Kwiatkowski is charged with obtaining controlled substances by fraud and tampering with a consumer product, U.S. Attorney John P. Kacavas said Thursday at a news conference in Concord.

Kacavas also announced a federal investigation identified hospitals in at least six other states where Kwiatkowski worked in the past. Investigators are trying to determine whether any other patients may have been exposed to the disease.

Prosecutors say Kwiatkowski spread the virus by stealing syringes of the anesthesia drug fentanyl, injecting himself with the drug, and then filling the syringes back up with a different liquid to conceal the theft. Kwiatkowski allegedly passed the disease to patients by allowing the syringes to be reused on patients.

On Wednesday, investigators also discovered Kwiatkowski was allegedly found to have stolen fentanyl while he was working as a contract employee at a hospital in another state in 2008. Prosecutors say Kwiatkowski was seen entering an operating room, lifting his shirt, and putting a syringe of fentanyl down his pants.

Kwiatkowski was searched after the procedure, and allegedly found to be carrying three empty syringes labeled as fentanyl. Prosecutors say a drug test administered after the 2008 incident also detected fentanyl and opiates in Kwiatkowski's urine.

“With Kwiatkowski's arrest today, this serial infecter has been contained and the menace he posed to public health and safety has been removed,” Kacavas said.

Kwiatkowski is originally from Michigan. He worked in the health care industry in Michigan for a several years, and went on to work as a traveling technician in cardiac catheterization laboratories in at least six states since 2007, according to an affidavit filed in federal court in New Hampshire Thursday.

Kwiatkowski was employed as a medical technician in Exeter Hospital's cardiac catheterization laboratory (CCL) between April 2011 and May 2012. He was first hired as a traveling technician, then brought on as a full staff member in October 2011, Kacavas said.

According to the affidavit, employees at Exeter Hospital were suspicious of Kwiatkowski's behavior before the outbreak of hepatitis C was detected at the hospital this spring. He was allegedly observed leaving the CCL during procedures, sweating profusely, attending procedures on his off-days, and “engaging in other suspicious behavior,” according to information provided by the U.S. Attorney's office.

One person identified as a “witness” reported Kwiatkowski appeared to be “on something,” and others claimed to have observed so-called “track marks” on his arms — physical signs of injection drug use.

During one instance, a supervisor declared Kwiatkowski unfit for work and sent him home early from a shift, according to information provided by Kacavas.

When federal authorities searched Kwiatkowski's vehicle, they allegedly found an empty fentanyl syringe and several needles inside, despite the fact that he should not have had access to the drug as a technician, according to Kacavas.

He declined to describe the exact method prosecutors believe Kwiatkowski employed to obtain the drug.

“In order to protect the integrity of our ongoing investigation, I'm not going to discuss his method,” he said.

Prosecutors say when Kwiatkowski was questioned regarding the hepatitis C outbreak at Exeter Hospital, he insisted he only learned he was carrying the disease in May 2012. However, investigators have allegedly uncovered evidence that Kwiatkowski has carried the disease since at least June 2010, Kacavas said.

According to the affidavit, Kwiatkowski was scheduled to appear in state court in Massachusetts on charges of misconduct after an automobile crash. He failed to appear in court, and a warrant was issued for his arrest. Then, on July 13, officers from the Marlborough, Mass., police department allegedly found Kwiatkowski intoxicated inside a hotel room. Police said he may been attempting to harm himself.

Kwiatkowski's backgroundTraveling workers such as Kwiatkowski are hired to work at hospitals on a contract basis for a short time, often approximately 13 weeks, according to information provided in the federal affidavit.

As part of their investigation, federal authorities have interviewed some of Kwiatkowski's former colleagues at other hospitals he worked in before being hired in Exeter.

Witnesses have painted a picture of Kwiatkowski as a man who often fabricated stories about himself: In one case, he claimed erroneously to have played baseball at the University of Michigan. In another instance, a witness said Kwiatkowski claimed his fiancee had died under tragic circumstances.

According to the affidavit, a former supervisor told police Kwiatkowski was fired for lying on his time sheets.

Multiple people also reported Kwiatkowski claimed to have cancer; investigators have found no evidence to support the claim.

On at least two occasions, needles were found inside a restroom at a hospital where Kwiatkowski was working while he was on duty, another former supervisor told police.

Behavior at Exeter HospitalIn June, police interviewed a range of employees and supervisors at Exeter Hospital, some of whom recalled Kwiatkowski's behavior was “unusual,” according to the affidavit. One recalled a day when she noticed he was sweaty and had bloodshot eyes. Believing he was “on something,” she notified the CCL director.

In a June 18, 2012, interview with investigators, the director acknowledged receiving the complaint. He said he called Kwiatkowski into his office and also observed that the technician's eyes were bloodshot. According to the affidavit, Kwiatkowski told the director that his aunt had died and that he had been up since 3 a.m. crying. He was sent home “in light of his condition,” according to the affidavit.

Last month, Kwiatkowski's parents were also interviewed by police. They indicated there have been no family deaths in recent years, according to the affidavit.

Another Exeter Hospital employee who was interviewed last month said he remembered an incident in which he observed that Kwiatkowski had “a red face, red eyes, and white foam around his mouth,” while he was on duty.

A third employee recalled that the family of an Exeter Hospital patient had found a syringe labeled “fentanyl” inside a public bathroom outside the CCL. The story has been corroborated by other employees, according to the affidavit.

In an interview with police, one of those employees recalled Kwiatkowski became “upset and claimed that the employee had accused him of stealing drugs,” when the employee raised the issue in a conversation, according to the affidavit.

Still, another worker said Kwiatkowski would sometimes get “shaky and very sweaty,” and would rush out of the CCL at the conclusion of some procedures.

One former co-worker at Exeter Hospital claimed that Kwiatkowski often complained of abdominal pain, had to go to the bathroom frequently, and also vomited regularly. The affidavit states that abdominal cramps, vomiting and sweating are symptoms often associated with fentanyl withdrawal.

Investigating KwiatkowskiOn June 19, 2012, federal agents in Michigan interviewed Kwiatkowski's parents. Kwiatkowski's parents said their son has issues with “alcohol, anger, and depression,” but claimed that they did not believe he used illegal drugs.

The couple said their son suffers from Crohn's disease, a bowel disorder, and took medications for the illness. They also indicated that Kwiatkowski was diagnosed with hepatitis C, and he became infected when he was pricked by a needle at work. They estimated Kwiatkowski was infected with the disease at least one year ago.

Kwiatkowski resided in Exeter while he was employed at the hospital, and investigators also interviewed a woman who previously lived with him. According to the affidavit, the woman claimed she found needles in Kwiatkowski's laundry on several occasions.

When she confronted him, Kwiatkowski told her the needles were related to cancer treatment he was receiving at Portsmouth Regional Hospital. She also told police she discovered a “blunt needle” under Kwiatkowski's bed.

An investigator who was shown the needle said it resembles the needles used in the CCL at Exeter Hospital to draw medication.

A footnote in the affidavit states the woman who formerly lived with Kwiatkowski subsequently failed a lie-detector test.

The layout at Exeter HospitalBased on their interviews with Exeter Hospital officials, prosecutors say Kwiatkowski should not have been granted access to drugs such as fentanyl, which are kept tightly controlled in hospitals.

The CCL at Exeter Hospital contains two secured machines to dispense controlled hospital narcotics, which are referred to as Pyxis machines. The first is kept in a secured room adjacent to the CCL recovery area. The second is inside the lab.

In order to access medications, nurses and other authorized individuals must enter a username and provide a fingerprint scan. Witnesses told investigators at the beginning of a procedure, a nurse will ordinarily remove vials of medication, such as fentanyl, draw the narcotics into syringes, then label them.

During procedures, the physician and scrub technician — the position held by Kwiatkowski — are considered sterile and are the only workers who come in contact with the patient's body. The nurse who administers the medications usually stands aside, behind a screen.

At the conclusion of the procedure, the nurse is required to discard any unused drugs by tossing needles and syringes in a medical waste container. Based on these circumstances, prosecutors say Kwiatkowski would have no reason to possess a syringe containing fentanyl or a needle used in a CCL procedure.

Lead aprons raise suspicionsOn June 15, investigators spoke with an Exeter Hospital CCL supervisor about the hepatitis C outbreak. The supervisor speculated one possible explanation for how Kwiatkowski could access medication while a procedure is under way is by delivering aprons to colleagues.

The supervisor said Kwiatkowski would sometimes deliver lead aprons to workers inside the procedure room, even if he wasn't assigned to work during the procedure.

The supervisor said Kwiatkowski would set the lead aprons down on a table next to the Pyxis machine, often after nurses had already withdrawn medications. According to the affidavit, the supervisor speculated this could have provided Kwiatkowski with an opportunity to steal syringes of fentanyl and replace them with tainted syringes containing saline or another liquid.

“He noted that it was unusual for an employee to bring in lead aprons for other employees,” the affidavit states.

Police interview KwiatkowskiKwiatkowski was interviewed by law enforcement officers on June 13, 2012. He allegedly told police he was recently informed by a doctor that he had tested positive for hepatitis C, and described the news as a “time bomb.” According to the affidavit, Kwiatkowski denied diverting any hospital drugs, and further stated he was allergic to fentanyl.

However, the investigation has uncovered Kwiatkowski received approximately 200 micrograms of fentanyl while undergoing a medical procedure on Dec. 11, 2011. The physician who operated on Kwiatkowski was interviewed on Wednesday, and told police that she saw no evidence of an allergic reaction to the drug.

The investigation into Kwiatkowski's activities took a turn on June 23, when one of his family members called the Exeter Police Department. According to the affidavit, the family member reported Kwiatkowski had a gun and was potentially suicidal.

Police in Boxborough, Mass., located Kwiatkowski at a hotel there. They searched his room and found no weapons, but allegedly discovered prescription bottles and clothing. Kwiatkowski agreed to be transported to a hospital for evaluation.

Therefore, police executed a federal search warrant on Kwiatkowski's vehicle. Inside, they allegedly found an empty syringe labeled with a blue sticker that read “fentanyl,” which “appears to be consistent with the stickers used to label syringes at the Exeter Hospital CCL,” according to the affidavit.

On July 2, Kwiatkowski was interviewed again by law enforcement officers. He allegedly admitted he had “lied to a lot of people” and “fabricated my life.” He denied being an injection drug user, and said the syringe allegedly found in his car was not his, and suggested it had been planted their by a co-worker.

Kwiatkowski allegedly terminated the interview when he was informed police had gathered evidence that he was aware before May 2012 of his hepatitis C diagnosis.